Android 中使用intent.putExtra实现Activity之间的参数传递

@Override
    public void onClick(View v) {
        Intent intent = new Intent(this,MainActivity2.class);
        //将要传递的值，附加给intent对象
        intent.putExtra("a1","hello");
        intent.putExtra("a2","hello2");
        startActivity(intent);
    }

@Override
    protected void onResume() {
        super.onResume();
        getBundleInfo();
    }
    private void getBundleInfo() {
        Bundle req=getIntent().getExtras();
        //取出intent中附加的数据,通过 键值对 来传递
        String a11=req.getString("a1");
        String a22=req.getString("a2");
        tv1.setText(a11);
        tv2.setText(a22);
    }